I’m sorry but number 1 for sandwiches?
Ridiculous.
How can you possibly hope to safely retain a good stack of filling in the rapidly narrowing sharp corners of a triangle?
There’s no support.
Sadly, the shape must usually be endured for shop bought sandwiches but you’ll notice that the posher and more generously filled ones tend to be cut as 2 or 3 for the customer with at least some sense of what’s right and wrong.
Science innit.
#1 generally works for me and you get o start with a corner, my problem is that I will stuff things into my gob by default so a sandwich format that forces me to take more bites is beneficial for me and anyone watching.
Granted though diagonal cutting doesn’t suit certain fillings like fish fingers, those do get cut rectangular.
As for artisanal tosspot shop bought sarnies, you’re being tricked it’s easy to add volume to a sandwich without you actually gaining much more they just double up on lettuce and pile the chicken or ham in the middle so it appears there’s more in there when cut in half, but they’re still going to add £1.20 to the asking price because you think your getting ‘more’ in your more structurally sound sandwich…